6.6-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long lucien.xin@gmail.com
[ Upstream commit 2ebe8f840c7450ecbfca9d18ac92e9ce9155e269 ]
As it says in commit 3bc07321ccc2 ("xfrm: Force a dst refcount before entering the xfrm type handlers"):
"Crypto requests might return asynchronous. In this case we leave the rcu protected region, so force a refcount on the skb's destination entry before we enter the xfrm type input/output handlers."
On TIPC decryption path it has the same problem, and skb_dst_force() should be called before doing decryption to avoid a possible crash.
Shuang reported this issue when this warning is triggered:
[] WARNING: include/net/dst.h:337 tipc_sk_rcv+0x1055/0x1ea0 [tipc] [] Kdump: loaded Tainted: G W --------- - - 4.18.0-496.el8.x86_64+debug [] Workqueue: crypto cryptd_queue_worker [] RIP: 0010:tipc_sk_rcv+0x1055/0x1ea0 [tipc] [] Call Trace: [] tipc_sk_mcast_rcv+0x548/0xea0 [tipc] [] tipc_rcv+0xcf5/0x1060 [tipc] [] tipc_aead_decrypt_done+0x215/0x2e0 [tipc] [] cryptd_aead_crypt+0xdb/0x190 [] cryptd_queue_worker+0xed/0x190 [] process_one_work+0x93d/0x17e0
Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Reported-by: Shuang Li shuali@redhat.com Signed-off-by: Xin Long lucien.xin@gmail.com Link: https://lore.kernel.org/r/fbe3195fad6997a4eec62d9bf076b2ad03ac336b.171847604... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/tipc/node.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/tipc/node.c b/net/tipc/node.c index 3105abe97bb9c..69053c0398252 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -2107,6 +2107,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b) } else { n = tipc_node_find_by_id(net, ehdr->id); } + skb_dst_force(skb); tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b); if (!skb) return;